How to Make It
Pull off the dark green outer leaves of the artichokes until you reach the pale green leaves. Cut off the top two-thirds of the leaves. Using a melon baller or spoon, scoop out the hairy chokes. Using a vegetable peeler or a paring knife, peel the stems and trim away any dark green portions from the bottoms. Rub the artichokes with the lemon half. Cut the artichokes in half lengthwise, then thinly slice them crosswise. Squeeze the lemon all over the artichokes.
In a saucepan, bring the stock to a boil; keep warm over low heat. Heat the olive oil in a large heavy saucepan. Add the artichokes, carrots, onion, celery and leek and cook over moderate heat for 5 minutes. Add the zucchini and cook, stirring occasionally, until the vegetables are crisp-tender, about 5 minutes longer. Add the rice and stir over moderate heat until translucent, 2 to 3 minutes. Add the wine and cook over moderately high heat, stirring, until absorbed. Add 1 cup of the stock and cook, stirring, until absorbed. Continue adding the stock, 1 cup at a time, stirring constantly until it is absorbed before adding more. The rice is done when it's tender and creamy but still firm to the bite, 20 to 25 minutes.
Stir the 1/2 cup of Parmesan and the butter, parsley, chives and basil into the risotto and season with salt and pepper. Spoon the risotto into shallow bowls and serve as soon as possible. Pass additional Parmesan at the table.